So its been a few weeks since the BTS trip now, found a few issues with the front axle and resolved them.... got a nice new tranny cooler installed to make room for the hopefully soon to be coming intercooler.... a few concerns im having. 1 i can still smell tranny fluid when the trucks sitting idling when its to operating temp. Not like burnt tranny fluid but like your standing in a tranny build room. fresh fluid smell.... not sure why... I look under there all the time checking to see if somethings leaking and i never come up with a leak. I haven't called Brian on this yet... and after changing to manual lockouts it smoothed up the 3 to 4 shift quite a bit but its still hitting much harder than the other shifts.... today i also noticed what feels like a lag between 2 and 3 i hadn't felt before. It doesn't set a code or anything it was just feeling like it was hesitating between the shift. I don't know if that is something i should be alarmed about or not. I don't know what right is really supposed to feel like so I have no way of telling right from wrong necessarily. 1 to 2 go nice and smooth, 2 to 3 feels hesitant and sometimes acts like its bogging the engine down. Ill be accelerating in 1 and 2 like I think it should and when it hits 2 to 3 sometimes it feels like ya suddenly dropped 1000 lbs in the bed and then itll pick itself back up again and be fine. 3 open to 3 lockup shifts flawlessly, then 3 to 4 hits like a brick wall. I had it stumble a little between 3 and 4 tonight as well. The way its programmed it shifts 3 lockup to 4 open and then goes to 4 lockup just after shifting, usually you can feel 2 hits when it does this. tonight i had it feel like 3 or 4 hits, it did that twice. and then the next time it went through the gears it didn't miss a beat..... I don't know what to think really. I don't want to bug Brian if it turns up to be nothing and at the same time I don't want to have something go catastrophically wrong with my truck either. which leads me to this question:


what is a limited slip differential supposed to act like? I had the truck jacked up on stands last weekend to change rear brakes. while it was up i put the trans in neutral and attempted to turn the rear wheels, the drivers side wheel turned very stiff compared to the passenger side, to the point it was nearly impossible to turn without my breaker bar on the lug nuts, and even then it was still very stiff, the passenger side took minimal effort to turn with the bar, there was some resistance but nothing like the drivers side. also grabbing the tire with both hands one on either side of the tire and rocking it forward and back there was a decent amount of free slop between when it would start turning the driveshaft. I had swapped the diff fluid over a year ago when i bought the truck and it didn't appear to be in bad shape, though again im an engine builder not a chassis guy, anything i learn on the chassis side i learn through working on my truck as needed.

what im thinking about doing is jacking the truck back up and pulling the axle shafts and checking resistance on the hub without the diff in play. if the resistance without the shaft is minimal then ill put the shafts back in and unhook the driveline and see if the diff is offering the resistance, and if its not the diff then it must be in the trans.

anybody have any insight on these issues? any advice on if im going the right direction with this diagnosis? any idea how much resistance there should be? is the limited slip causing the resistance on one side and not the other when there is no load on either wheel (both jacked up in the air)??? i don't seem to recall large amounts of resistance with my ZF5 in neutral on my 94 with open diff.

 

Sure sounds like a parking brake hung up or brakes adjusted too tight on the one side. I wouldn't worry much with the other until the brake issue is resolved.

 

I agree with Aaron on the diff. I wonder what the odds of your shifting issue being linked to your motor. The problem is you won't know unless you finish the supporting mods (e-fuel, hpop) or contact brian. I'd call him anyway just to ask about the fluid smell

 

I checked the parking brake when I changed the shoes and ensured they were both released as much as possible.. and I never touch the park brake pedal. And no one else has driven my truck since I did the rear brakes. I don't think it would be engine related, as I rarely run the truck above 30-40% throttle and I have good hpop pressure down that low and fuel pressure at idle is 60ish psi. The hub itself on the drivers side with no tire and no brake drum was also very hard to turn. To the point ya almost couldnt budge it by hand.

 

sounds then like the shoes are adjusted too tight then

 

If there was no brake drum, then it may be the wheel bearings. Try backing them off and readjusting them if they are still in good shape. But, if it is the bearings, and they been running that tight, I doubt they are in good shape.

 

Was the axle shaft back in or still out when you were turning the hub without the brake drum?

 

Axle shafts weren't out then, I haven't had time to tear it back down, probably won't tell next weekend. I just wanted to get some insight on the proper operation on the axle, I'm hoping if there is an issue it just ends up being wheel bearings, I just don't know if the diff is supposed to be causing resistance, especially on one side more than the other being limited slip...

 

Well I pulled the axle shaft out and jacked the drivers side up, wheel turned free with no shaft, very minimal brake drag. With the 1 side up and the trans in neutral there is quite a bit of play when ya grab the drives haft and roll it back and forth.

 

Well I think I found an issue, after reinstalling the shaft went out and drove some more, still hesitating between 2 and 3 and brick walling between 3 and 4.... when I got back my gf mom was out feeding the animals and came by the truck and said something smells.... I've had a sinus infection so the sniffer ain't workin that great. Pulled the stick and got real close and yeppp that is the smell of burnt tranny fluid.

 

Wow......not good.

 

yea, i don't really know why, fluid levels still good. tranny temp never got over 180 max. according to the edge insight.

 

I hate to hear that the new trans is having problems. I'm sure Brian will take of you of you though if there is a problem.

 

I'm hoping so, I really don't like this, especially since its so new, the only thing I've done with it thats not really on highway driving is a week an a half ago we had a snow storm and I had to do some 4 wheelin to get out of the house and back to the main highway, were about 5-10 miles from the state highway.... and we had probably 4-6 inches of snow on the ground

 

I don't think that would have hurt anything at all. I mean, that's what you're supposed to do with a 4wd right? LOL! I'd definitely be on the phone first thing in the morning though.